Computers, including but not limited to personal computers (PCs) and personal digital assistants (PDAs) use operating systems having predetermined file structures. The file structures are adapted for interfacing with mechanical drives (e.g., hard drives and floppy drives). Data can be written directly over other data designated for deletion.
Flash memory cards are configured in erase blocks, which must be completely erased prior to any data being written within a particular erase block.
A flash translation layer has been developed to interface between flash memory card erase blocks and the file system used by a PC operating system. One such FTL is described in U.S. Pat. No. 5,404,485 which issued in 1995. The FTL connects flash memory cards to the file system used by the operating system of a particular PC, not allowing more than one write without erase at the same address.
The conventional practice of background clean-up operations interspersing primary read and write activities creates complications and difficulties in maintaining updated FTL tables and other structures of the FTL essential to operation.